JP4744581B2 - Power transmission device for vehicle - Google Patents

Description

  The present invention includes a transmission mechanism that is housed in a case and capable of transmitting power between a plurality of rotating elements, and is mounted on a vehicle and transmits power from a power generation source to an axle via the transmission mechanism. The present invention relates to a power transmission device.

Conventionally, as this type of vehicle power transmission device, a torque converter, an oil pump, a forward / reverse switching mechanism, a continuously variable transmission unit, a gear train, a difference, and the like housed in a case including a converter housing, a transaxle case, and a rear cover. One including a moving mechanism (differential gear) or the like is known (see, for example, Patent Documents 1 and 2). In this vehicle power transmission device, power from the engine is transmitted to the continuously variable transmission unit via the torque converter and the forward / reverse switching unit, and is continuously shifted by the continuously variable transmission unit, and then the gear train and the difference are transmitted. It is transmitted to the left and right drive wheels via a moving mechanism.
JP 2004-183714 A JP 2004-36633 A

  By the way, in the vehicle power transmission device as described above, a lubricating medium pumped by an oil pump is supplied to a bearing that supports a rotating shaft such as a primary shaft and a secondary shaft of a continuously variable transmission unit. The differential mechanism and the like disposed at the lower part in the case are lubricated mainly by the lubricating medium stored at the bottom in the case. On the other hand, the intermediate gear of the gear train that transmits the power from the secondary shaft of the continuously variable transmission unit to the differential mechanism and the bearing that supports the shaft of the intermediate gear are basically the drive wheels. It is lubricated by a lubricating medium that is picked up by other gears along with the rotation or carried along the other gears. For this reason, for example, under conditions where the ambient temperature is extremely low, sufficient lubrication medium does not reach the shaft of the intermediate stage gear that is not forcedly supplied with the lubrication medium or the bearing that supports the shaft. If the rotational speed of the intermediate gear is increased, the temperature of the shaft of the intermediate gear and the bearing that supports the shaft may be excessively increased.

  SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide a vehicle power transmission device that can satisfactorily lubricate a lubrication target that is not forcedly supplied with a lubricating medium.

  The vehicle power transmission device according to the present invention employs the following means in order to achieve the main object.

The vehicle power transmission device according to the present invention is:
A vehicle power transmission device including a transmission mechanism that is housed in a case and capable of transmitting power between a plurality of rotating elements, and that is mounted on a vehicle and transmits power from a power generation source to the axle via the transmission mechanism Because
An uppermost bearing fixed to the case and rotatably supporting the shaft of the uppermost rotating element located on the uppermost side in the case among the rotating elements included in the transmission mechanism;
A lower bearing that is fixed to the case and rotatably supports the shaft of the lower rotating element that is positioned below the uppermost rotating element among the rotating elements included in the transmission mechanism when mounted;
An uppermost lubricating medium reservoir defined between the uppermost bearing and the case so that the lubricating medium can be guided to the uppermost bearing;
The vehicle power transmission device is defined between the lower bearing and the case so as to be positioned below the uppermost lubricating medium reservoir and to guide the lubricating medium to the lower bearing when the vehicle power transmission device is mounted. A lower lubricating medium reservoir,
A communication path formed in the case so as to communicate the uppermost lubricating medium reservoir and the lower lubricating medium reservoir;
Is provided.

  In this vehicle power transmission device, among the rotating elements included in the transmission mechanism, the shaft of the uppermost rotating element located on the uppermost side in the case when mounted is rotatably supported by the uppermost bearing fixed to the case, Of the rotating elements included in the transmission mechanism, the shaft of the lower rotating element positioned below the uppermost rotating element is mounted on a lower bearing fixed to the case so as to be rotatable. In addition, an uppermost lubricating medium reservoir is defined between the uppermost bearing and the case so that the lubricating medium can be guided to the uppermost bearing. Sometimes the lower lubricating medium reservoir is defined so as to be positioned below the uppermost lubricating medium reservoir and to guide the lubricating medium to the lower bearing. The uppermost lubricating medium reservoir and the lower lubricating medium reservoir are communicated with each other through a communication path formed in the case. Thus, when the lubricating medium is supplied to the uppermost lubricating medium reservoir, the lubricating medium is guided from the uppermost lubricating medium reservoir to the uppermost bearing, and the lubricating medium is stored in the lower lubricating medium via the communication path. It flows down to the part and is guided from the lower lubricating medium storage part to the lower bearing. Therefore, in this vehicle power transmission device, if the lubricating medium is supplied to the uppermost lubricating medium reservoir, the lubricating medium is not supplied forcibly to the lower bearing as the lubrication target. It becomes possible to lubricate the lower bearing satisfactorily.

  The vehicular power transmission device may further include a lubricating medium supply unit capable of forcibly supplying a lubricating medium to the uppermost lubricating medium reservoir. As a result, it is possible to stably supply the lubricating medium to the uppermost lubricating medium reservoir and to better lubricate the lower bearing.

  Further, the communication path may extend along a line connecting the axis of the uppermost rotation element and the axis of the lower rotation element. Thereby, it becomes possible to form the opening part of the communicating path with respect to the uppermost lubricating medium reservoir part and the opening part of the communicating path with respect to the lower lubricating medium reservoir part so as not to cause stress concentration, thereby improving the durability of the case. be able to.

  The uppermost lubricating medium reservoir is defined by the uppermost bearing and the side wall of the case, and the lower lubricating medium reservoir is formed by the lower bearing and the side wall of the case. The communication path may have a depth that gradually decreases from the uppermost lubricating medium reservoir to the central portion and gradually increases from the central portion to the lower lubricating medium reservoir. The concave part formed in the side wall part of the said case may be sufficient. Thereby, even if a concave communication path is formed in the side wall portion of the case, the rigidity of the side wall portion of the case is ensured without hindering the flow of the lubricating medium from the uppermost lubricating medium storage portion to the lower lubricating medium storage portion. It becomes possible.

  Further, the transmission mechanism may be a gear train including at least three gears, and the uppermost rotation element is an uppermost member located on the uppermost side in the case when mounted on a gear included in the gear train. The lower rotating element may be between the uppermost gear and the lowermost gear located on the lowermost side in the case among the gears included in the gear train. It may be an intermediate gear located.

  Further, the lowermost gear may be a gear that scoops up the lubricating medium at the inner bottom portion of the case toward the center inside the case without following the inner wall surface of the case when the axle is normally rotated. The uppermost gear may be a gear that rotates in the same direction as the lowermost gear during forward rotation of the axle. That is, this vehicle power transmission device is positioned at the lowest side in the case among the gears included in the gear train when mounted on the vehicle, and the lubricating medium at the inner bottom of the case is used as the inner wall surface of the case when the axle is rotating forward. It has a lowermost gear that is scraped toward the center inside the case without being along, and has a structure in which the structure of a conventional vehicle power transmission device is mirror-inverted. Thereby, in a vehicle equipped with this vehicle power transmission device, the wheel base can be easily extended. In this way, the lowermost gear scrapes the lubricating medium at the inner bottom of the case toward the center inside the case without following the inner wall surface of the case when the axle is rotating forward, and the uppermost gear is the axle. If the motor rotates in the same direction as the lowermost gear during normal rotation, a sufficient amount of lubricating medium may not be conveyed from the lowermost gear to the intermediate gear. However, as described above, the uppermost lubricating medium If the storage portion and the lower lubricating medium storage portion are communicated with each other through the communication path, a sufficient amount of the lubricating medium can be guided to the intermediate gear. Therefore, in a vehicle equipped with this vehicle power transmission device, the wheel base can be easily extended and a lubrication target that is not forcedly supplied with a lubricating medium can be well lubricated.

  The vehicle power transmission device according to the present invention may further include a continuously variable transmission unit that is housed in the case and capable of continuously transmitting power from the power generation source to the gear train. Preferably, the vehicle is a front-wheel drive vehicle, the lowermost gear is a differential ring gear connected to a differential mechanism, and the primary shaft of the continuously variable transmission unit is on the vehicle rear side with respect to the lowermost gear when mounted on the vehicle. May be located. As a result, in a front-wheel drive vehicle equipped with this vehicle power transmission device, the wheel base can be easily extended, and a lubrication target that is not forcedly supplied with a lubricating medium can be well lubricated.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a schematic configuration diagram showing a power transmission device (transmission) according to an embodiment of the present invention. A power transmission device 20 shown in the figure is applied to a front-wheel drive vehicle and transmits power from an engine (not shown) mounted on the front of the vehicle to left and right front wheels, and is integrally coupled to a converter housing 21a, A case 21 including a transaxle case 21b and a rear cover 21c, a torque converter 22, an oil pump 30, a forward / reverse switching unit 35, and a belt-type continuously variable transmission unit (hereinafter referred to as "CVT") housed in the case 21 40, a gear mechanism (gear train as a transmission mechanism) 60, a differential mechanism (differential gear) 66, and the like. In other words, in a vehicle equipped with this power transmission device 20, power from the engine is transmitted to CVT 40 via torque converter 22 and forward / reverse switching unit 35, and is shifted steplessly by CVT 40 and then gear mechanism 60. And transmitted to the left and right front wheels via the differential mechanism 66.

  The torque converter 22 is configured as a fluid torque converter with a lock-up clutch, and is accommodated in the converter housing 21a. As shown in FIG. 1, the torque converter 22 is disposed inside a pump impeller 23 connected to an engine crankshaft (not shown), a turbine runner 24 fixed to an input shaft 41 of the CVT 40, the pump impeller 23, and the turbine runner 24. It includes a stator 25 arranged, a one-way clutch CO that restricts the rotational direction of the stator 25 to one direction, a lock-up clutch 28 having a damper mechanism 27, and the like. The torque converter 22 operates as a torque amplifier when the rotational speed difference between the pump impeller 23 and the turbine runner 24 is large, and operates as a fluid coupling when the rotational speed difference between the two becomes small. When the vehicle speed reaches a predetermined speed after the vehicle starts, the pump impeller 23 and the turbine runner 24 are locked by the lock-up clutch 28 so that the power from the engine is mechanically and directly transmitted to the input shaft 41. become. At this time, the fluctuation of the torque transmitted to the input shaft 41 is absorbed by the damper mechanism 27.

  The oil pump 30 is configured as a so-called gear pump including a pump assembly 33 including a pump body 31 and a pump cover 32 disposed between the torque converter 22 and the forward / reverse switching unit 35 and an external gear 34. . The pump body 31 and the pump cover 32 are fixed to the converter housing 21a and the transaxle case 21b. The external gear 34 is connected to the pump impeller 23 via a hub, and forms a crescent with internal teeth (not shown) formed in the pump body 31. Thus, when the external gear 34 is rotated by the power from the engine, the working fluid (ATF) stored in the oil pan 80 (see FIG. 2) is sucked by the oil pump 30 and the sucked working fluid is Since the pressure is increased, the hydraulic pressure (line pressure) required by the CVT 40 or the forward / reverse switching unit 35 is generated, or the lubrication target such as a predetermined portion of the CVT 40, the one-way clutch CO, the forward / reverse switching unit 35, or various bearings. It is possible to supply a working fluid as a lubricating medium.

  The forward / reverse switching unit 35 is housed in the transaxle case 21b, and includes a double pinion planetary gear mechanism 36, and a hydraulic brake B1 and a clutch C1 that operate using working fluid from the oil pump 30. . The planetary gear mechanism 36 includes a sun gear fixed to the input shaft 41 of the CVT 40, a ring gear, a pinion gear that meshes with the sun gear, and a carrier that supports the pinion gear meshed with the ring gear and is coupled to the primary shaft 42 of the CVT 40. The brake B1 can fix the ring gear of the planetary gear mechanism 36 with respect to the transaxle case 21b and can be freely rotated. The clutch C1 uses the carrier of the planetary gear mechanism 36 as an input shaft 41 (sun gear). On the other hand, it can be fixed and rotated. As a result, when the brake B1 is turned off and the clutch C1 is turned on, the power transmitted from the torque converter 22 to the input shaft 41 can be transmitted to the primary shaft 42 of the CVT 40 as it is to advance the vehicle. Further, by turning on the brake B1 and turning off the clutch C1, the rotation of the input shaft 41 is converted in the reverse direction and transmitted to the primary shaft 42 of the CVT 40, so that the vehicle can be moved backward. Further, the connection between the input shaft 41 and the primary shaft 42 can be released by turning off the brake B1 and turning off the clutch C1.

  The CVT 40 is housed inside the transaxle case 21b and the rear cover 21c, and has a primary shaft 42 as a drive side rotating shaft extending coaxially with the input shaft 41, a primary pulley 43 provided for the primary shaft 42, A secondary shaft (output shaft) 44 as a driven side rotating shaft extending in parallel with the primary shaft 42, a secondary pulley 45 provided for the secondary shaft 44, and the primary pulley 43 and the secondary pulley 45 are wound around Belt 46. The primary pulley 43 includes a fixed sheave 43a formed integrally with the primary shaft 42, and a movable sheave 43b supported on the primary shaft 42 through a roller spline or the like so as to be slidable in the axial direction. A hydraulic cylinder (hydraulic actuator) 47 for changing the groove width of the primary pulley 43 is formed behind the movable sheave 43 b of the primary pulley 43. The secondary pulley 45 includes a fixed sheave 45a formed integrally with the secondary shaft 44, and a movable sheave 45b supported by the secondary shaft 44 so as to be slidable in the axial direction via a roller spline, a return spring, or the like. Is done. A hydraulic cylinder (hydraulic actuator) 48 for changing the groove width of the secondary pulley 45 is formed behind the movable sheave 45 b of the secondary pulley 45. For the hydraulic cylinder 47 on the primary pulley 43 side and the hydraulic cylinder 48 on the secondary pulley 45 side, the working fluid pressurized by the oil pump 30 is adjusted by a hydraulic circuit (valve body) (not shown) including a plurality of control valves. Is supplied after being pressurized, thereby changing the groove widths of the primary pulley 43 and the secondary pulley 45 and continuously changing the power input from the input shaft 41 to the primary shaft 42 and outputting it to the secondary shaft 44. It becomes possible to do. As shown in FIG. 1, one end (right end in the figure) of the secondary shaft 44 is formed by a bearing (roller bearing) 90 fixed to the converter housing 21a and a bearing (roller bearing) 91 fixed to the transaxle case 21b. While being rotatably supported, the other end of the secondary shaft 44 is rotatably supported by a bearing (ball bearing) 92 fixed to the rear cover 21c.

  The gear mechanism 60 is accommodated inside the converter housing 21a and the transaxle case 21b, and is mounted on one end side of a counter drive gear 61 fixed to one end of the secondary shaft 44 and a counter shaft 62 extending in parallel with the secondary shaft 44. A counter driven gear 63 that is fixed and meshes with the counter drive gear 61, a drive pinion gear (final drive gear) 64 that is fixed to the other end of the counter shaft 62, and a drive pinion gear 64 that meshes with the differential mechanism 66. Differential ring gear (final driven gear) 65. When the power transmission device 20 is mounted on the vehicle, as shown in FIG. 2, the diff ring gear 65 is positioned at the lowermost side in the case 21 among the gears included in the gear mechanism 60, and the counter drive gear 61 is Of the gears included in the gear mechanism 60, the gear mechanism 60 is positioned on the uppermost side in the case 21. As shown in FIG. 1, the differential mechanism 66 is fixed to a differential case 67 that is rotatably supported in the case 21 and connected to the differential ring gear 65, and a shaft that is rotatably supported by the differential case 67. A pair of pinion mate gears (bevel gears) 68 and a pair of side gears 69 that mesh with the respective pinion mate gears 68 are respectively fixed to the left and right differential shafts 70a and 70b as front wheel axles. ing. As shown in FIG. 1, one end (right end in the figure) of the counter shaft 62 is rotatably supported by a bearing (roller bearing) 93 fixed to the converter housing 21a, and the other end of the counter shaft 62 ( The left end in the figure is rotatably supported by a bearing (roller bearing) 94 fixed to the transaxle case 21b.

  Here, the power transmission device 20 of the embodiment has a structure in which a structure of a general power transmission device for a front wheel drive vehicle is mirror-inverted. In other words, a general power transmission device for a front-wheel drive vehicle is configured to be mounted on a vehicle such that a diff ring gear (differential mechanism) is located on the vehicle rear side with respect to the primary shaft of the CVT. As shown in FIG. 2, the power transmission device 20 according to the embodiment is configured to be mounted on the vehicle such that the diff ring gear 65 (differential mechanism 66) is located on the vehicle front side relative to the primary shaft 42 of the CVT 40. Has been. As a result, in the vehicle equipped with the power transmission device 20, the wheel base, which is the distance between the front and rear axles, can be easily extended, so that the indoor space, the cargo space, and the like can be enlarged. In FIG. 2, the right side in the figure is the vehicle front (F) side and the left side in the figure is the vehicle rear (R) side.

  For example, when the vehicle equipped with the power transmission device 20 is towed by another vehicle in a state where four wheels are installed due to a failure or the like, the oil pump 30 cannot be driven because the engine is stopped. The working fluid as the lubricating medium cannot be supplied to the object to be lubricated by using 30. Further, since the pressure of the working fluid cannot be increased to the line pressure by the oil pump 30 at the time of towing, both the brake B1 and the clutch C1 of the forward / reverse switching unit 35 are released, and the secondary pulley 45 side The groove width of the primary pulley 43 is maximized (the effective radius of the primary pulley 43 is minimum) and the groove width of the secondary pulley 45 is minimized (the effective radius of the secondary pulley 45 is maximum). Underdrive state. For this reason, when the vehicle is towed, the primary shaft 42 of the CVT 40 is overdriven with respect to the differential shafts 70a and 70b serving as axles, and the primary shaft 42 rotates at a relatively high speed. It is necessary to lubricate the forward / reverse switching unit 35 connected to.

  Based on this, in the power transmission device 20 of the embodiment, as shown in FIG. 2, a hole 31 a is formed in the pump body 31 constituting the oil pump 30 so as to be positioned at the top when the power transmission device 20 is mounted on the vehicle. The pump cover 32 is formed with a lubricating flow path 32a extending from the outer peripheral side toward the center. When the power transmission device 20 is mounted on the vehicle, the pump cover 32 is disposed in the case 21 so that the outer peripheral side end of the lubrication flow path 32a is positioned in front of the vehicle and the center side end is positioned in the rear of the vehicle. The road 32a is inclined downward toward the rear of the vehicle. The lubrication flow path 32a communicates with a hole 31a as an inlet for the working fluid through a groove formed on the surface of the pump body 31 on the pump cover 32 side, and supports a one-way clutch CO and the like. 26 communicates with the gear, brake B1, and clutch C1 peripheral portions of the forward / reverse switching unit 35 through a groove and a hole formed in 26, a gap between the stator sleeve 26 and the input shaft 41, and the like. Thus, when the vehicle on which the power transmission device 20 is mounted is pulled, the case 21 (in the embodiment, the converter housing 21a and the housing 21a and the differential housing 65 located in the lowermost side in the case 21 among the gears included in the gear mechanism 60). If the working fluid is scooped up from the inner bottom of the transaxle case 21b) and guided to the hole 31a of the pump body 31 by the gear mechanism 60, the action of gravity causes the hole 31a, the lubrication flow path 32a of the pump cover 32, etc. Thus, it is possible to supply a working fluid as a lubricating medium to the gear, brake B1, clutch C1, and the like of the forward / reverse switching unit 35 as a lubrication target.

  However, since the power transmission device 20 of the embodiment has a structure in which the structure of a general power transmission device for a front wheel drive vehicle is mirror-inverted, the lowermost differential ring gear 65 includes differential shafts 70a and 70b. When the vehicle moves forward and moves forward, the working fluid accumulated in the inner bottom portion of the case 21 does not follow the inner wall surface of the transaxle case 21b as shown by the two-dot chain arrow in FIG. It will be scraped up toward the center. Therefore, if no measures are taken, the working fluid pumped up by the lowermost diffring gear 65 is not carried by the gear mechanism 60, and in the embodiment, it is positioned on the vehicle rear side of the diffring gear 65 and below the CVT 40. As a result, the oil flows into the oil pan 80 attached to the case 21, and when the vehicle is towed, the working fluid as the lubricating medium cannot be sufficiently supplied to the forward / reverse switching unit 35 to be lubricated, There is a possibility that the working fluid in the inner bottom portion of the case 21 to be scraped up by the ring gear 65 is insufficient. Therefore, a partition wall 21w is formed in the transaxle case 21b so as to extend upward from the bottom of the case and surround a part of the outer periphery of the diff ring gear 65 on the center side inside the case. As shown in FIG. 2, the partition wall 21 w surrounds the outer periphery of at least the lower half of the diff ring gear 65 at the center side inside the case, that is, the outer periphery of at least the lower quarter of the vehicle rear side (left side in the figure). Formed. In the embodiment, the upper end portion of the partition wall 21 w operates as a meshing portion between the drive pinion gear 64 and the diff ring gear 65 as an intermediate gear between the diff ring gear 65 and the counter drive gear 61 as shown in FIG. Positioned so that fluid can be directed. Further, in the embodiment, the partition wall 21w has a width equal to the internal width of the case 21 (a length comparable to the counter shaft 62) so that a necessary and sufficient working fluid can be stored in the case inner bottom portion around the differential ring gear 65. ). Thereby, the partition wall 21w defines the accommodating part of the diff ring gear 65 and the differential mechanism 66 with the converter housing 21a and the inner wall surface of the transaxle case 21b. The housing portion for the diff ring gear 65 and the like is formed in a side wall portion 21 aw facing the engine side surface of the diff ring gear 65 of the converter housing 21 a and extends in parallel with the diff shafts 70 a and 70 b, that is, the diff ring gear 65. The oil pan 80 communicates with the inside through a communication path including a flow path extending along the axial direction.

  By forming such a partition wall 21w inside the converter housing 21a and the transaxle case 21b, the working fluid scooped up by the diff ring gear 65 can be better meshed with the diff ring gear 65 and the drive pinion gear 64 as an intermediate gear. It is possible to direct to the part. However, in the power transmission device 20 of the embodiment, as shown in FIG. 2, the rotational directions of the lowermost diffring gear 65 and the uppermost counter drive gear 61 coincide. Accordingly, the working fluid which is scraped up by the diff ring gear 65 and guided by the partition wall 21 w and guided to the meshing portion between the drive pinion gear 64 and the diff ring gear 65 and carried upward by the drive pinion gear 64 is rotated by the counter drive gear 61. As a result, the counter driven gear 63 serving as the intermediate gear and the counter drive gear 61 are guided to the meshing portion, and the working fluid may fall to the oil pan 80 without being guided further upward. For this reason, the transaxle case 21b encloses a part of the outer periphery of the uppermost counter drive gear 61 and is scraped up by the diff ring gear 65 and the working fluid carried by the drive pinion gear 64 and the diff ring gear 65 is lubricated. A guide wall 21g is provided to guide to the hole 31a of the pump body 31 which is the inlet of 32a. As shown in FIG. 2, the guide wall 21g extends from the inner surface of the side wall portion of the transaxle case 21b so as to surround the upper half of the outer periphery of the uppermost counter drive gear 61, and the transaxle case 21b. A circular arc-shaped flow path 21p that faces the hole 31a is defined together with the upper inner wall surface. The end of the guide wall 21g on the side of the hole 31a extends substantially horizontally so that the working fluid from the flow path 21p is appropriately stored and appropriately flows into the hole 31a. The end opposite to the 31a side receives the working fluid carried by the differential ring gear 65 and the drive pinion gear 64 and suppresses the falling of the working fluid to the meshing portion of the counter drive gear 61 and the counter driven gear 63. Positioned. Thereby, in the power transmission device 20 of the embodiment, as shown by a dotted line in FIG. 2, the working fluid scraped up by the diff ring gear 65 is guided to the meshing portion of the drive pinion gear 64 and the diff ring gear 65 by the partition wall 21w. The working fluid conveyed upward by the drive pinion gear 64 is guided to the flow path 21p defined by the guide wall 21g and the upper inner wall surface of the transaxle case 21b, and the working fluid that has entered the flow path 21p is counter-driven. Without being influenced by the rotation of the gear 61, it is possible to lead to the hole 31a which is the inlet of the lubrication flow path 32a by the action of gravity. In the embodiment, the guide wall 21g is configured as a series of members. However, the guide wall 21g is not limited to this. For example, the guide wall 21g is divided into a plurality of parts such as a part surrounding the counter drive gear 61 and a part forming an oil sump. May be.

  In the power transmission device 20 according to the embodiment, the guide wall 21g is provided in the case 21 in consideration of the lubrication of the forward / reverse switching unit 35 at the time of towing, but the guide wall 21g allows the working fluid to flow through the channel 21p. Since the main purpose is also to guide to the countershaft, the amount of the working fluid guided to the meshing portion of the counter driven gear 63 and the counter drive gear 61 is reduced, and thereby the bearing that supports the countershaft 62 There is a risk that the working fluid staying in the vicinity of 93 and 94 will be insufficient. If the working fluid supplied to the bearings 93 and 94 is insufficient in this way, for example, when the driving wheel (the diff ring gear 65) rotates at a very high speed while the ambient environment temperature is extremely low, the bearings 93, There is also a possibility that the temperature of 94 and the countershaft 62 supported by it will increase excessively.

  In view of these points, the power transmission device 20 according to the embodiment does not change the total amount of working fluid used for the lubrication of the entire device, and is the uppermost in the case 21 in the gear 21 of the gear mechanism 60 when mounted. The working fluid that lubricates the bearings 90 and 91 of the secondary shaft 44, which is the shaft of the counter drive gear 61 positioned on the side, meshes with the counter drive gear 61 by the action of gravity, and the counter driven gear 63 and the drive positioned below the counter drive gear 61 are driven. It is configured to be supplied to bearings 93 and 94 of a counter shaft 62 that is an axis with the pinion gear 64.

  That is, the bearing 90 that supports one end (the right end in FIG. 1) of the secondary shaft 44 that is the shaft of the counter drive gear 61 is formed on the inner surface of the side wall portion 21aw of the converter housing 21a, as shown in FIGS. It is fitted and fixed to the uppermost bearing mounting portion 201 which is a concave portion. When the bearing 90 is fixed to the uppermost bearing mounting portion 201 in this way, there is a hole formed in the secondary shaft 44 or a gap between the spline fitting portion between the secondary shaft 44 and the counter drive gear 61 between them. The uppermost working fluid reservoir 201a that can store a certain amount of working fluid is defined by receiving a working fluid from an oil pump 30 through an oil passage (not shown) (see FIG. 1). The Thereby, if the working fluid as a lubricating medium is supplied to the uppermost working fluid reservoir 201a, the bearing 91 and the secondary shaft 44 communicated with the bearing 90 and the hole of the secondary shaft 44 from the uppermost working fluid reservoir 201a. The working fluid from the oil pump 30 is guided to a spline fitting portion or the like with the counter drive gear 61, and these elements can be forcibly lubricated. Further, as shown in FIGS. 3 and 4, a bearing 93 that supports one end (the right end in FIG. 1) of the counter shaft 62 that is an axis of the counter driven gear 63 and the drive pinion gear 64 is provided on the side wall 21 aw of the converter housing 21 a. It is fitted and fixed to a lower bearing mounting portion 203 which is a recess formed on the inner surface. When the bearing 93 is fixed to the lower bearing mounting portion 203 in this way, a spline fit between the hole formed in the counter shaft 62 and the counter shaft 62 and the counter driven gear 63 or the drive pinion gear 64 is provided between them. A lower working fluid reservoir 203a is defined which communicates with the gaps of the parts and can store a certain amount of working fluid.

  And uppermost side working fluid storage part 201a and lower side working fluid storage part 203a are mutually connected by the communicating path 202 which is a recessed part formed in the inner surface of side wall part 21aw of converter housing 21a. In the embodiment, the communication path 202 extends along a straight line connecting the axis of the secondary shaft 44 and the axis of the counter shaft 62 with the shortest distance, as indicated by a one-dot chain line in FIG. Further, as shown in FIG. 4, the communication path 202 gradually decreases in depth as it goes from the uppermost bearing mounting portion 201 toward the central portion and gradually increases from the central portion toward the lower bearing mounting portion 203. Is formed. That is, the inner surface of the communication path 202 is formed so that the central portion in the extending direction is gently raised (see FIG. 4). Thereby, a part of the working fluid as the lubricating medium supplied to the uppermost working fluid reservoir 201a by the oil pump 30 flows down to the lower working fluid reservoir 203a via the communication path 202 by the action of gravity. The working fluid flowing into the lower working fluid reservoir 203a is guided to the bearing 93, the bearing 94 communicating with the hole of the counter shaft 62, the spline fitting portion between the counter shaft 62 and the counter driven gear 63 and the drive pinion gear 64, and the like. This makes it possible to lubricate these elements (natural lubrication).

  As described above, in the power transmission device 20 according to the embodiment, among the gears included in the gear mechanism 60 serving as the transmission mechanism housed in the case 21, the counter drive gear positioned at the uppermost side in the case 21 when mounted. A secondary shaft 44, which is an axis of 61, is rotatably supported by bearings 90 and 91 as uppermost bearings fixed to the case 21, and is lower than the counter drive gear 61 when mounted on the gear included in the gear mechanism 60. The counter shaft 62 that is the shaft of the counter driven gear 63 and the drive pinion gear 64 positioned on the side is rotatably supported by bearings 93 and 94 as lower bearings fixed to the case 21. Further, an uppermost working fluid reservoir 201a is defined between the bearing 90 and the side wall 21aw (case 21) of the converter housing 21a so that the working fluid as a lubricating medium can be guided to the bearing 90 and the like. In addition, between the bearing 93 and the side wall 21aw (case 21) of the converter housing 21a, the lubricating medium can be guided to the bearing 93 and the like while being positioned below the uppermost working fluid reservoir 201a when mounted on the vehicle. A lower working fluid reservoir 203a is defined. And uppermost side working fluid storage part 201a and lower side working fluid storage part 203a are mutually connected by communication path 202 formed in converter housing 21a. As a result, when a working fluid as a lubricating medium is supplied to the uppermost working fluid reservoir 201a, the working fluid is guided from the uppermost working fluid reservoir 201a to the bearings 90 and 91, and is lowered via the communication path 202. It flows down to the side working fluid reservoir 203a and is guided from the lower working fluid reservoir 203a to the bearings 93 and 94. Therefore, in the power transmission device 20 of the embodiment, if the working fluid is supplied to the uppermost working fluid reservoir 201a, the working fluid as the lubricating medium is forcibly supplied to the bearings 93 and 94 as the lubrication target. Even if it is not done, it becomes possible to lubricate the said bearings 93 and 94 favorably.

  In the power transmission device 20 of the embodiment, since the working fluid is forcibly supplied from the oil pump 30 to the uppermost working fluid reservoir 201a, the working fluid is stably supplied to the uppermost working fluid reservoir 201a. At the same time, a sufficient amount of working fluid can be supplied from the uppermost working fluid reservoir 201a to the lower working fluid reservoir 203a to better lubricate the bearings 93 and 94. Further, the communication path 202 of the embodiment extends along a straight line connecting the axis of the secondary shaft 44 that is the axis of the counter drive gear 61 and the axis of the counter shaft 62 that is the axis of the counter driven gear 63 and the drive pinion gear 64. It exists. As a result, stress is applied so that the periphery of the opening portion of the communication passage 202 with respect to the uppermost working fluid reservoir 201a and the shape of the periphery of the opening portion of the communication passage 202 with respect to the lower working fluid reservoir 203a do not include extremely sharp points. It is possible to prevent concentration, and the durability of the case 21 (converter housing 21a) can be improved. In the above embodiment, the uppermost working fluid reservoir 201a is defined between the bearing 90 and the side wall 21aw of the converter housing 21a, and the lower working fluid reservoir 203a is defined between the bearing 93 and the converter housing 21a. The communication path 202 is defined between the side wall portion 21aw and the depth of the communication path 202 gradually decreases from the uppermost working fluid reservoir 201a toward the central portion and from the central portion toward the lower working fluid reservoir 203a. A concave portion is formed in the side wall portion 21aw of the converter housing 21a so as to gradually increase. Thereby, even if the concave communication path 202 is formed in the side wall portion 21aw of the converter housing 21a, the side wall portion 21aw does not hinder the flow of the lubricating medium from the uppermost working fluid reservoir 201a to the lower working fluid reservoir 203a. It is possible to ensure the rigidity.

  Furthermore, the power transmission device 20 according to the embodiment is positioned on the lowermost side in the case 21 among the gears included in the gear mechanism 60 when the vehicle is mounted, and when the differential shafts 70a and 70b as front wheel axles are rotated forward. And a diffring gear 65 that scoops up the working fluid in the inner bottom of the case 21 toward the center inside the case without being along the inner wall surface of the case 21, and is a mirror image of the structure of a general power transmission device for a front-wheel drive vehicle It has an inverted structure. Therefore, in a vehicle equipped with the power transmission device 20, the primary shaft 42 of the CVT 40 is positioned on the vehicle rear side with respect to the diff ring gear 65 and the differential mechanism 66 when mounted on the vehicle, so that the wheel base can be easily extended. it can. In this way, the lowermost differential ring gear 65 scoops up the working fluid at the inner bottom portion of the case 21 toward the center inside the case without following the inner wall surface of the case 21 when the differential shafts 70a and 70b are rotated forward. If the counter drive gear 61 on the uppermost side rotates in the same direction as the differential ring gear 65 when the differential shafts 70a and 70b are rotated forward, the counter driven gear 63 or the drive pinion gear 64 as an intermediate gear from the differential ring gear 65 is used. However, if the uppermost working fluid reservoir 201a and the lower working fluid reservoir 203a are connected by the communication path 202 as described above, there is a possibility that a sufficient amount of the working fluid (lubricating medium) may not be conveyed. A sufficient amount of working fluid can be guided to the counter driven gear 63 and the drive pinion gear 64. Therefore, in the vehicle on which the power transmission device 20 is mounted, the wheel base can be easily extended, and a lubrication target that is not forcedly supplied with the working fluid as a lubricating medium can be well lubricated.

  The embodiments of the present invention have been described above using the embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention. Needless to say.

  The present invention can be used in the manufacturing industry of power transmission devices for vehicles.

It is a schematic block diagram of the power transmission device 20 which concerns on the Example of this invention. It is a fragmentary sectional view showing the inside of transaxle case 21b of power transmission device 20 of an example. It is a fragmentary sectional view showing the inside of converter housing 21a of power transmission device 20 of an example. It is a partial expanded sectional view which shows the principal part of the converter housing 21a of the power transmission device 20 of an Example.

Explanation of symbols

  20 Power transmission device, 21 case, 21a converter housing, 21aw side wall, 21b transaxle case, 21c rear cover, 21g guide wall, 21h hole, 21p flow path, 21w partition wall, 22 torque converter, 23 pump impeller, 24 turbine runner , 25 Stator, 26 Stator sleeve, 27 Damper mechanism, 28 Lock-up clutch, 30 Oil pump, 31 Pump body, 31a Hole, 32 Pump cover, 32a Lubrication flow path, 33 Pump assembly, 34 External gear, 35 Back and forth Switching unit, 36 planetary gear mechanism, 40 continuously variable transmission unit (CVT), 41 input shaft, 42 primary shaft, 43 primary pulley, 43a, 45a fixed sheave, 43b, 45b movable shaft , 44 secondary shaft, 45 secondary pulley, 46 belt, 47, 48 hydraulic cylinder, 60 gear mechanism, 61 counter drive gear, 62 counter shaft, 63 counter driven gear, 64 drive pinion gear, 65 diff ring gear, 66 differential mechanism, 67 differential case, 68 pinion mate gear, 69 side gear, 70a, 70b differential shaft, 80 oil pan, 90, 91, 92, 93, 94 bearing, 201 uppermost bearing mounting portion, 201a uppermost working fluid reservoir (uppermost lubrication) Medium reservoir), 202 communication path, 203 lower bearing mounting portion, 203a lower working fluid reservoir (lower lubricating medium reservoir), B1 brake, C1 clutch, CO one-way clutch.

Claims (6)

A vehicle power transmission device including a transmission mechanism that is housed in a case and capable of transmitting power between a plurality of rotating elements, and that is mounted on a vehicle and transmits power from a power generation source to the axle via the transmission mechanism Because
An uppermost bearing fixed to the case and rotatably supporting the shaft of the uppermost rotating element located on the uppermost side in the case among the rotating elements included in the transmission mechanism;
A lower bearing that is fixed to the case and rotatably supports the shaft of the lower rotating element that is positioned below the uppermost rotating element among the rotating elements included in the transmission mechanism when mounted;
An uppermost lubricating medium reservoir defined between the uppermost bearing and the case so that the lubricating medium can be guided to the uppermost bearing;
The vehicle power transmission device is defined between the lower bearing and the case so as to be positioned below the uppermost lubricating medium reservoir and to guide the lubricating medium to the lower bearing when the vehicle power transmission device is mounted. A lower lubricating medium reservoir,
A communication path formed in the case so as to communicate the uppermost lubricating medium reservoir and the lower lubricating medium reservoir;
With
The uppermost lubricating medium reservoir is defined by the uppermost bearing and the side wall of the case, and the lower lubricating medium reservoir is defined by the lower bearing and the side wall of the case. And the side wall of the case has a depth that gradually decreases from the uppermost lubricating medium reservoir to the central portion and gradually increases from the central portion to the lower lubricating medium reservoir. Ri recess der formed,
The transmission mechanism includes a counter drive gear fixed to a shaft rotatably supported by the uppermost bearing as the uppermost rotating element, and is rotatable by the lower bearing as the lower rotating element. A drive pinion gear fixed to a supported countershaft and carrying a lubricating medium upward during forward rotation of the axle; and a counterdriven gear fixed to the countershaft and meshing with the counterdrive gear;
A guide portion that surrounds a part of the outer periphery of the counter drive gear and guides a lubricating medium carried by the drive pinion gear to an inlet of a lubricating flow path for guiding a lubricating medium other than the uppermost bearing and the lower bearing. A vehicle power transmission device further provided . The vehicle power transmission device according to claim 1 ,
Steplessly variable power that is housed in the case and transmitted from the power generation source to the primary shaft and can be transmitted to the transmission mechanism from the secondary shaft that is rotatably supported by the uppermost bearing. A transmission unit;
The power transmission device includes a diff ring gear that meshes with the drive pinion gear and is coupled to a differential mechanism. The vehicle power transmission device according to claim 2 ,
The diff ring gear is a vehicle power transmission device that is a gear that scoops the lubricating medium at the inner bottom of the case toward the center of the case without following the inner wall surface of the case when the axle is normally rotated. The power transmission device for a vehicle according to claim 3 ,
A vehicle power transmission device further comprising a partition wall extending upward from the inner bottom portion of the case and surrounding a part of an outer periphery of the diff ring gear on a central side inside the case. The uppermost lubricating medium reservoir vehicle power transmission device according to claim 1, further comprising a forcibly supplied lubrication medium supply means a lubricating medium in any one of 4 to. The vehicular power transmission device according to any one of claims 1 to 5 , wherein the communication path extends along a line connecting the axis of the uppermost rotation element and the axis of the lower rotation element.

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